This disclosure generally relates to an electromechanical machine, and more particularly to a rotor assembly for an electromechanical machine.
In aeronautical applications, an electromechanical machine, such as a generator, is often used to supply power to an aircraft, for example. The power produced by the generator is routed and distributed throughout the aircraft via a power generation and distribution system. In some instances, the aircraft may use a single electromechanical machine as both a starter and a generator, such as a dynamoelectric machine, for example.
Electromechanical machines as described above typically include a rotor assembly having a plurality of poles including a plurality of field windings. The field windings generate the electromagnetic flux necessary to induce a magnetic field within a stator assembly of the electromechanical machine. The rotor assembly also includes a damper circuit. For example, the poles each include a plurality of slots that receive a plurality of damper bars. The electromagnetic flux is communicated through the damper bars. A pair of copper end-plates are received at each end of a rotor core of the rotor assembly to electrically connect the damper circuit.
Electromechanical machines having rotor assemblies of this type are heavy and costly to manufacture. Numerous brazing operations are required to fabricate the rotor assembly because each damper bar must be brazed to the copper end-plates to electrically connect the damper circuit.
In addition, the damper bars and the slots the damper bars are received in may create flux pinch points that limit the communication of the electromagnetic flux to the stator assembly. The flux pinch points occur at the location of the damper bars because the electromagnetic flux must “bend” around each of the damper bars. The flux pinch points create increased exciter and main field current flow. The increased exciter and main field current flow necessitates an increase in the size and weight of the electromechanical machine. The increased size and weight of the electromechanical machine negatively impacts aircraft efficiency.